Front Mesh making back mesh impossible to see, help?
You can hide the vertices you don't want to see. Just select the ones you want to hide and press H.

Also, the reference image will only show when you're aligned with an axis and in orthographic mode—hit 1, 3, 5, or 7 on the numpad to align the view, and then 5 to go into orthographic mode.*

*The manual says that orthographic mode is the default in Blender, but it's not.